Is it possible to create 3D-Images like this one:
with LaTeX (preferably tikz)? How do you do it? Are there good tutorials / documentations?
(I have seen some examples from tikz-3dplot, but these images always have axis (e.g. this or those) and the colors don't look as nice as in the image above)
As @canaaerus said, it is possible to do such images in Tikz, but it is not a good idea. Tikz processing is slow for complicated pictures, and even if it may process transparency and 3D coordinates (this is all in the PGF reference), you will work much better with a dedicated software and export either to PNG, PDF or even tikz for some programs. The partial illumination effects for example would be really hard to get right with Tikz. My advice: use the tool best adapted to your graphics.
Note also that transparency in PDF sometimes does not work correctly with certain printers (especially for posters; the processing software is sometimes old on these machines ; I've had this problem several times a few years ago), so bitmap is sometimes a better idea (and tikz does not generate bitmaps). Using a better-suited program with export capabilities will ensure that you can produce high-quality documents and printables documents.
LaTeX. It usually takes a lot of time to compile such fancy plots and you are quite limited in what you can do. Better use something dedicated likeblenderto create the images.tikz-3dplotlibrary) by addinghide axisto theaxisoptions.